John Bond has been appointed chairman of Xstrata. Photograph: Attila Kisbenedek/AFP/Getty Images

Xstrata severed a crucial link with Glencore on Monday ahead of the Swiss-based commodity trader's possible £40bn London listing, replacing the man who chairs both companies with City grandee Sir John Bond.

Bond, who has chaired Vodafone and HSBC, will join Xstrata's board immediately as a consultant and become chairman after the AGM in May. He will replace the veteran Willy Strothotte who has chaired Xstrata since 1994, guiding it through its flotation nine years ago and subsequent rapid expansion by acquisition to make it a major FTSE 100 player.

He has also been chairman of Glencore, Xstrata's biggest shareholder with a 34% stake, since 2001.

The private commodities trader also has a series of commercial arrangements with the mining company, shares in which are widely seen as having been discounted in the market on the back of its close links with Glencore.

With suggestions that Xstrata could eventually merge with Glencore, there are fears that their close relationship could see any merger dilute value in the miner. There are few listed commodities traders, making it hard to assess what value Glencore would offer in a Xstrata deal.

Glencore gave a briefing to analysts in London last week amid mounting speculation of a pre-Easter float, and Xstrata said on Monday that part of its thinking in changing its chairman was linked to the possible listing. "Willy Strothotte has been chairman of Xstrata for nine years and prior to that served as chairman of the former Xstrata AG for eight years. Given this tenure and the board's view that, if Glencore seeks a public listing, it would not be appropriate for Xstrata to have a Glencore nominee as its chairman, the nominations committee initiated an external search for a candidate last autumn," a spokeswoman said.

Strothotte is also set to lose his role as chairman of Glencore, given that he was chief executive of the Swiss trading group and would not, under best practice corporate governance rules, be able to chair the listed entity after a London IPO.

As part of its flotation plans Glencore has been drawing up a shortlist of candidates for Strothotte's role, with reports at the weekend suggesting Petrofac chairman Rodney Chase was set to take up the role. Sources close to Glencore insisted on Monday that such suggestions were premature, and that Glencore had up to 50 possible names for the chairman's role.

As well as a chairman, it is seeking non-executive directors to ensure it meets corporate governance requirements.

Shares in Xstrata, whose has assets include extensive coal, nickel and copper resources, were down 10p on Monday on the news of its new chairman, to £14.15.

Glencore rival Trafigura, meanwhile, has moved its trading operations in London to Geneva.

Reports suggested the company had moved its asset management arm last week, for tax reasons and also to centralise European trading operations from a single base.

"Basically they are centring the trading operations in Geneva. So the majority of trading teams will be there," Reuters quoted a trader saying. "It makes a lot of sense on different fronts – lifestyle too."

Galena Asset Management, a subsidiary of the Trafigura Group, was set up in London in 2004 and has $1.4bn under management for hedge fund clients.

Trafigura declined to comment.

Grandee on board

Sir John Bond has, on the face of it, an impeccable CV: a banker at HSBC at 21, he rose to executive chairman. He moved before the financial crisis hit to become chairman of Vodafone, which was in the midst of a boardroom row.

But his work at both HSBC and Vodafone has had its critics. Bond was a key figure in 2003 when HSBC bought Household, the US consumer finance group. There was controversy over high payouts to Household's executives and its sub-prime losses caused considerable damage to HSBC.

Bond was criticised by the Ontario Teachers' Pension Plan, a key investor, towards the end of his tenure at Vodafone over strategic weaknesses at the company and what it termed its "disastrous" acquisition record. However, he comfortably saw off the attack at last year's annual meeting.

Married with three children, his eldest daughter, the climber Annabelle Bond, has said that he has "a killer stare. If I've done something wrong, he doesn't raise his voice or stamp his feet: his look says it all. It can have me quaking in my shoes."